Caffeine addicts nationwide got first tastes of Starbucks Corp.’s newest offering as the coffee giant blanketed the nation with tens of thousands of free samples of its instant coffee called Via.

The beverage, which comes in a long cylindrical plastic sleeve and dissolves in a cup of water, debuted nationwide Tuesday after months of preliminary sales in test markets.

Starbucks employees handed out free samples of Via and mixed up drinks for customers from coast to coast as part of the chain’s quest to convince customers that instant coffee – long viewed as inferior by U.S. coffee drinkers – can taste as good as brewed.

Verdicts from an unscientific sampling of customers ranged from a tentative thumbs-up to serious skepticism.

“I can’t tell the difference,” said Margaret Vazquez, 39, who was waiting in line for her regular Starbucks brewed coffee in San Francisco’s financial district Tuesday morning. “But that could be because it’s the first coffee I’ve had today.”

Backed by national television ads – a rarity for the company – along with large-scale distribution to about 1,500 sites outside its stores, the Via launch shows just how determined Starbucks is to own a stake in the $21 billion worldwide instant coffee market.

It was formulated during nearly two decades of research by the Seattle-based coffee giant, which is hoping to stake a claim on the $21 billion global market for the insta-brews.

While instant coffee is pervasive throughout Europe – accounting for as much as 80 percent of coffee sales in the U.K. – the beverage hasn’t won over American taste buds, in large part because of their image as an inferior knockoff of drip-brewed beverages.

But it’s that perception that Starbucks executives are trying to change. They hope Via’s 3-packs ($2.95) and 12-packs ($9.95) will eventually be as prevalent on store shelves as its packaged coffee is now.